can vary the common bond with a Flemish header
course. In laying out any bond pattern, be sure to start
the corners correctly. In a common bond, use a three-
quarter closure at the corner of each header course.
In the Flemish bond, each course consists of
alternating headers and stretchers. The headers in every
other course center over and under the stretchers in the
courses in between. The joints between stretchers in all
stretcher courses align vertically. When headers are not
required for structural bonding, you can use bricks,
called blind headers. You can start the corners in two
different ways. In the Dutch corner, a three-quarter
closure starts each course. In the English corner, a 2-inch
or quarter closure starts the course.
The English bond consists of alternating courses
of headers and stretchers. The headers center over and
under the stretchers. However, the joints between
stretchers in all stretcher courses do not align
vertically. You can use blind headers in courses that
are not structural bonding courses.
The stack bond is purely a pattern bond without
overlapping units; however, all vertical joints are
aligned. You must use dimensionally accurate or
carefully rematched units to achieve good vertical
joint alignment. You can vary the pattern with
combinations and modifications of the basic patterns
shown in figure 4-4. This pattern usually bonds to the
backing with rigid steel ties or 8-inch-thick stretcher
units when available. In large walled areas or
load-bearing construction, insert steel pencil rods into
the horizontal mortar joints as reinforcement.
The English cross, or Dutch, bond is a variation of
the English bond. It differs only in that the joints
between the stretchers in the stretcher courses align
vertically. These joints center on the headers in the
courses above and below.
When a wall bond has no header courses, use metal
ties to bond the exterior wall brick to the backing
courses. Figure 4-5 shows three typical metal ties.
Install flashing at any spot where moisture is likely
to enter a brick masonry structure. Flashing diverts the
moisture back outside. Always install flashing under
horizontal masonry surfaces, such as sills and copings;
at intersections between masonry walls and horizontal
surfaces, such as a roof and parapet or a roof and
chimney; above openings (doors and windows, for
example); and frequently at floor lines, depending on the
type of construction. The flashing should extend through
the exterior wall face and then turn downward against
the wall face to form a drop.
Figure 4-5.Metal ties.
You should provide WEEP HOLES at intervals of
18 to 24 inches to drain water to the outside that might
accumulate on the flashing. Weep holes are even more
important when appearance requires the flashing to
stop behind the wall face instead of extending through
the wall. This type of concealed flashing, when
combined with tooled mortar joints, often retains
water in the wall for long periods, and by concentrating
the moisture at one spot, it does more harm than good.
MORTAR JOINTS AND POINTING
No set rule governs the thickness of a brick
masonry mortar joint. Irregularly shaped bricks may
require mortar joints up to one-half inch thick to
compensate for the irregularities. However, mortar
joints one-fourth inch thick are the strongest. Use this
thickness when the bricks are regular enough in shape
to permit it.
A slushed joint is made simply by the deposit of
mortar on top of the head joints and allowing it to run
down between the bricks to form a joint. You cannot
make solid joints this way. Even when you fill the
space between the bricks completely, there is no way
you can compact the mortar against the brick faces;
consequently, a poor bond results. The only effective
way to build a good joint is to trowel it.
The secret of mortar joint construction and
pointing is in how you hold the trowel for spreading
mortar. Figure 4-6 shows the correct way to hold a
trowel. Hold it firmly in the grip, as shown, with your
thumb resting on top of the handle, not encircling it. If
you are right-handed, pick up the mortar from the
outside of the mortar board pile with the left edge of
your trowel (fig. 4-7, view 1). You can pick up enough
to spread one to five bricks, depending on the wall